The present invention relates to new substituted pyridine or piperidine compounds and to their use as facilitators of memory and cognition and as antalgic agents.
Ageing of the population due to increased life expectancy has brought with it a major increase in cognitive disorders associated with normal cerebral ageing and with pathological cerebral ageing occurring in the course of neurodegenerative diseases such as, for example, Alzheimer""s disease.
The majority of substances used today in treating cognitive disorders associated with ageing act by facilitating the central cholinergic systemsxe2x80x94either directly, as in the case of acetylcholinesterase inhibitors (tacrine, donepezil) and cholinergic agonists (nefiracetam), or indirectly, as in the case of nootropic agents (piracetam, pramiracetam) and cerebral vasodilators (vinpocetine).
Besides their cognitive properties, substances acting directly on the central cholinergic systems often have antalgic properties but also have hypothermic properties, which can be undesirable.
It has been therefore been especially valuable to synthesise new compounds that are capable of opposing the cognitive disorders associated with ageing and/or of improving cognitive processes and that can possess antalgic properties without having hypothermic activity.
The literature discloses substituted piperidine compounds which are described as products of synthesis and/or of alkaloids (J. Chem. Soc., Perkin Trans. 1, 1991, (3), pp. 611-616; Heterocycles, 1985, 23 (4), pp. 831-834; Can. J. Chem., 1996, 74 (12), pp. 2444-2453).
Substituted pyridine compounds have also been described with reference to their synthesis (J. Chem. Soc., Dalton Trans., 1998, (6), pp. 917-922) or their interactions in metal complexes (J. Chem. Soc., Chem. Commun., 1987, (19), pp. 1457-1459; J. Am. Chem. Soc., 1985, 107 (4), pp. 917-925).
The compounds of the present invention are new and have properties that, from a pharmacological point of view, are especially valuable.